The present invention relates to a tap for controlling the flow of a fluid, comprising a tap body, an inner member for opening and closing the passage of the fluid, an outer rotary operating member, a connection means connecting the operating member to the closing member and means limiting the movement of the operating member and of the opening and closing member in the opening direction of the tap.
Although not being limited to this, the invention relates, more particularly, to a tap for bottles or tanks containing compressed or liquefied gas. In this type of tap, the connection means may be a rod and the means for limiting the movement in the opening direction generally consist of one or two spindles passing through the body of the tap in the transverse direction perpendicularly to the movement of the rod and tangentially relative to the latter. For this purpose, the rod comprises, in its central region, an annular contraction allowing the passage of the two spindles and the rotation of the rod. These two spindles and the base of the contraction form abutments and counterabutments defining the end of travel of the rod and the stopping of the opening movement of the tap.
The disadvantage of this known system is that, at the end of movement and since the tap is generally opened fully, the two spindles approach the bottom of the contraction of the rod tangentially on account of the rotation of the rod. Consequently, contact between the rod and the spindle or spindles is frictional or rubbing contact, that is to say progressive clamping and even jamming of the tap in the opening position occurs.
This clamping or jamming of the tap requires a great amount of manual force when the tap is to be closed and prompts the use of a tool, such as pliers. This may, however, give rise to carelessness and has already caused accidents on opening the tap. To be precise, it has already happened that an operator, wanting to release the tap by means of a tool, has turned the operating member in the wrong direction, that is to say in the opening direction, until the head of the tap has fractured. This may obviously present a serious risk if the gases are toxic or explosive.
The object of the present invention is to provide a novel tap of the type described in the introduction, which does not have this disadvantage, that is to say a tap without the risk of clamping or jamming when the tap is opened fully.
In order to achieve this object, the invention proposes a tap of the type described in the introduction, which is characterized in that said means limiting the movement of the operating member consist of an abutment and a counterabutment with frontal contact, which are arranged respectively on a rotary element and on the body of the tap, or vice versa.
Since there is no frictional contact between the abutment and counterabutment, there is no risk that the tap will become clamped or jammed. The operator can easily close the tap without exerting excessive force and without risking making a mistake over the direction of rotation and tightening the tap even more.
During opening and at the penultimate turn in the rotation of the operating member, the abutment and counterabutment do not yet come into contact, which means that, when they stop the rotation of the operating member, they are in mutual contact over a height which is smaller than the pitch of the threads between the rotary elements and the body of the tap.